Engine starting aid



Dec. 17, 1963 c. D. sNELLlNG 3,114,360

ENGINE STARTING AID Filed Jan, 17, 1962 BY Mp9 ATTORNEY ses 3,l14,360 ESTARTING All) Charles D. Snelling, Breinigsvilie, Pa. Filed 17, 1952,Ser. No. loo-S 6 laims. (lll. 323-1425) rl`his invention relates to aselective warm-up device for self-starting, engine-driven vehicles, and,in particular, to

a warm-up device adapted to maintain the normal starting characteristicsof an engine assembly under sub-freezing conditions which normallyadversely aiect the starting operation of heat engines of, for example,the internal combustion type.

he starting of engine-driven vehicles, such as automobiles, trucks,tanks, and the like, presents a problem in extremely cold climates,particularly in the arctic regions. v/here such difficulties arise, itis not uncommon to resort to the well known expedient of warming up acold selected portion of an engine assembly by the direct application ofheat by, for example, a blow torch or similar directh ating devices. Inthe case of the internal-combustion engine, the selected portion oi theengine assembly to be heated might comprise the oil pan beneath theengine and/ or the oil pan containing transmission lluid where anautomatic transmission system is involved, the radiator, the carburetor,the fuel-injection line or other selected portions in which a duid isinvolved, the performance of w ich is usually adversely affected byabnormal, subfreezing conditions.

The use of direct-heating devices present the problem of localizedover-heating and, unless a great deal of care is taken, damage of thepart being heated is apt to occur. The use of other methods involving,for example, the transfer of heat by the convection ilow of hot gases,such as by placing a heat source below the engine, have not proved totoo elicient, particularly in extremely cold environments.

I have found that l can overcome the disadvantages of prior methods byproviding a method of bringing heat under controlled conditions dire tlyto the selected part of the engine assembly to be heated by means of adirect application of heat at a portion of a heat-transfer system emoteand separate from said selected part of the engine assembly. Thus, withmy invention, I may, if I desire, use a blow torch as the heat source,but instead of applying the heat directly from the torch to theei'lccted part, apply heat directly to a heat-conductive element of aheat-transfer system, the location of direct-heat application beingremote from the selected part to be heated, and l conduct tie heat undersubstantially controlled-temperature conditions direct to said selectedpart to be heater.

in one embodiment of my invention, l may, in applying heat to aconductive element remote from the engine, store some or said heatenergy in a heat-storage device and call on the stored energy when it isneeded to warn up one or more selected parts oi an envi-ne assembly.

lt is therefore an obiect of my invention to provide a selective warm-updevice for use in combination with a self-starting engine powered by ahydrocarbon iluid and having selected portions including oil reservoirmeans, means for carbureting said hydrocarbon fluid, means for feedingsaid hydrocarbon lluid to said engine, fluid means for cooling saidengine and the like, the performance of one or more of which may beadversely aliected by aggravating, sub-freezing environments.

Another object is to provide a selective warm-up device characterized bya heat-storage means capable of receiving and retaining heat for a givenlength or time and of controliably releasing it when desired fortransfer to a Edi/lg3d@ Patented Bec. il?, 1963 selected portion of aheat engine to be warmed up for starting purposes.

As a further object, l provide a method for controllably transferringheat to a selected portion of a heat engine by indirect means from aprimary heat source.

These and other obiects will more clearly appear from the disclosure andthe accompanying drawings, wherein:

FIG. l depicts one embodiment of my invention utilizing a heat-storagemeans in combination with means for charging heat thereto in acontrollable heat-transfer system for transrnittinfY heat via heatexchangers to an oil-reservoir means of a heat-engine assembly;

PEG. 2 illustrates another embodiment ol my invention in which a meansis provided for receiving a concentrated application of heat forsubsequent transfer under controlled-temperature conditions to aselected portion of a heat-engine assembly such as the oil pan;

FIG. 3 shows means by which the outside casing of a carburetor can beadapted for receiving an indirect application o heat; and

FG. 4 depicts one embodiment of a heat-storage device chargeableelectrically by means of heating elements connectable to a source ofpower supply, for example from an automobile battery.

`Sroadly stated, my invention provides in combination with a heat enginea selective warm-up device which includes means for developing a heatsource, a rst heatexchanger means in heat-exchangeable relationship withsaid heat-developing source, at least a second heat-eX- changer means inexchanging relationship with a least one selected portion or aheat-engine assembly desired to be warmed up, heat-transfer meansconnectably associated with said heat-exchanging means at the heatsource and with said heat-exchanger means at the selected portion ofsaid heat-engine assembly. ln a preferred ernbodiment, I may use controlmeans associated with said heat-transfer means for connectably effectingheat transfer lrorn said heat-source developing means to said selectedportion of the heat-engine assembly.

ln carrying ou-t the broad method aspect of my invention, l apply heatdirectly to a heat-conductive element which has associated with it inheat-conductive relationship a reservoir, a substantial portion of whichis preferably insulated from the environment. rlhe reservoir forms partyof a sealed System and contains a heat-exchanging fluid whereby saiduid is caused to evaporate over a range of temperatures. The methodfurther includes conduct of the evaporated fluid to a selected portionof the engine to be warmed and maintaining it in neat-exchangingrelationship with said :selected portion, whereby the lluid gives up itsheat to said portion and condenses; finally, the condensed luid isreturned to the reservoir for repeated heating. Where I use a blow`torch for heating the heat-conductive element, I am not confronted bydamage to any engine part, since no part of the engine would be touchedby the torch.

As another preferred embodiment, l propose to use a heat-storage meansin conjunction with the heat conductive element so that, during theheating thereof, I can store the heat for subsequent release to theheat-transfer .system associated with the engine. In this connection,lrefer to FIG. l which shows somewhat diagrammatically and partially incross section a known heat-engine assembly indicated generally by thenumeral l@ comprising a crank shaft ll with main bearings l2 andconnecting rod 4bearings ll3. A camshaft lli is shown provided with camsida and camshaft ybeanings l5. A piston lo is depicted with connectingrod Ji. An oil header l is diagrammatically indicated fed from oilreservoir i9 via oi-l strainer 2t? and oil pump 2l through oil line ZZ.The oil header feeds oil as shown by the heavy lines branching`therefrom to main bearings `12, connecting-rod bearings 11, camshaftbearings i5, the bearings within the piston, and the like an oilpressure gauge 23 being also provided to indicate adequate oil feed.

Oil pan 24 is taken as illustrative of one of the selected portions otthe heat engine assembly to be heated and is shown jacketed by heatexchanger 25 to provide space 26 for receiving heat exchange iluid fromother por-tions of a heat-transfer system.

The system shown in FIG. l should not be taken as illustrating theproportion of the elements constituting the system, since it has beennecessary to exaggerate the proportioning for purposes of clarity. Theother parts of the system comprise heat-conductive element 27 formed ofa block of heat-conductive metal, such as copper, having an exposed faceadapted to receive the direct application of heat 28, as from a blowtorch.

In this embodiment, element Z7 is heat conductively associated withheat-storage device 29, which may also be of copper, having containedtherein a fusible salt 29a capable of a relatively high heat of fusion.In heatconducting relationship with container 29 is heat exchangerorvevaporator containing a heat-exchanger or thermodynamic fluid 3lproperly chosen for its operating characteristics in the system, capableof boiling at a given temperature. The two containers are substantiallyinsulated from the environment by insulation 32 `of asbestos or othermaterial. A heat-transfer line 33 is provided coupling the evaporatorSti with the oil pan at 34, a iiuid return line 35 being providedleading from outlet 36 of the oil pan to inlet 37 of fluid storagereservoir 38. Where gravity feed-back of the condensed fluid is notpossible, a pump 39 is provided to transfer the condensed fluid tostorage resem/oir 33 which is also.

preferably insulated by asbestos or other material `40. Insulation isalso preferred forexternally opposed parts of the pan 25 as well as thesupply and return parts Vfor the heat-exchanger iluid, but this has beenomitted changer uid is dependent on a number of factors, in-

cluding the following:

V(l) lt must be chemically stable and noncorrosive in the systemthroughout the anticipated range of temperatures.

(2) It should have as high a heat of vaporization as possible.

(3) It should boil in a pressure range that can be conveniently handledWithout resort to special techniques, for example, in the rangeextending between in. Hg to 50 p.s.1.g.

(4) It should be characterized by relatively high vapor density.

With the foregoing system, I am enabled-to store heat in container 29While at the same time heating the fluid in container 3% by applyingheat directly via a blow torch at 28 on the exposed face of element 27.After the Vblow torch is removed, the sensible and `latent heat storedin the fused salt 29a continues to effect heating of the fluid incontainer 3@ which evaporates, passes through line 33 into the oil panheat exchanger at 34 where lit gives up its heat to the oil, condensesand leaves the heat exchanger at 36 via pump 39' which delivers thecondensed `fluid to iluid reservoir 3:'5 through inlet 37. With thismethod, overheating of the oil pan isjavoid-ed, While 4 at Vthe sainetime warming up this portion of the engine assembly.

ln a simple embodiment shown .in FIG. 2, I may employ just a iluidheat-exchanger 45, suitably insulated by material i6 but inheat-conductive relationship with heatconductive element 47 having anexposed face for receiving the direct application of heat 46. Byapplying heat `to element 47, iluid boils, evaporates `and is conductedvia heat-transfer tube Sli` to heat exchanger S2 comprising a seriesconnected length of tubing at the bottom of oil pan 53. As the fluidcondenses and heats up the oil, it is adapted to return by gravity vialine 54 to the bottom of container 4S, as determined by the setting of amanual control valve 51. An advantage of this system is that it may beportable and used only when the occasion arises merely by connecting'lines Si! and 54 to appropriate connecting points of .theheat-exchanger associated with the oil pan. in this embodiment, thefluid may be water or other uid of higher or lower so-called boilingpoint depending on the requirements.

While the invention has been `described where the selected portion ofthe heat-engine assembly is the oil pan, it will be appreciated thatother selected portions generaillyV adversely aiected by sub-freezingmay also be similarly heated. Thus, I may Warm the casing of thecarburetor should it be necessary. Referring toFIG. 3, an outline or acarburetor casing 55 is indicated partially broken away at 56 at thereservoir side of the carburetor. The casi-ng is. shown surrounded by aheat-exchanger jacket 57 having an inlet 5S Vfor receivingheat-exchanger fluid from a remotely situated evaporator of the type'shown in FIGS. 1 and 2 and an outlet S9 from which the condensed Viluidexits to oe returned to a uid reservoir or directly to the evaporator.

A similar' arrangement may be used to warm up the radiator or otherselected portion of the engine assembly, the performance of which is`adversely Iaffected by Subfreezing temperatures.

Instead of using the type of heating indicated for FIGS. l and 2, l maystore up heat in the heat-storage portion of the system by theelectrical application of heat. For example, the heat-storage systemshown in FlG. 4 may be used comprising an electrical heating element 6i)in heat-conductive relationship with heat-storage container 61, whichyin turn is in heat-conductive relationship with evaporator 62, the twocontainers being surrounded by Vinsulator 63 of asbestos or lothermaterial to keep heat loss from the system down to a minimum. Athermostatic element 64 is provided in the region of the heatstoragebath in cooperative relationship with thermostat 65 for actuating saidheating element when the temperature of the heat-storage device dropsbelow a particular value. The heat-exchanger circulation yline (notshow-n) connected to inlet 65 and exit 57 of the heating system may beprovided with `automatic valves actuated by a temperature-sensing deviceassociated with a selected portion of the engine assembly to which heatis to be transferred. The power supply may be from .an externalelectrical trickle charge or from the battery in the vehicle, or it maybe the excess power generated while the engine is ruiming. Thus, where avehicle is being used intermittently in -a cold clima-te, theheat-storage device could be charged while the vehicle is running sothat when the vehicle is idle, the stored heat can be utilized to keepone or more portions of the engine assembly warm.

Examples of substances which may be used in the fused state as heatstorage means are: sodium dibasic phosphate (Na2HPO- 12H20) which meltsat about 96.8 F. yand sollidiiies to yield 12() Btu/lb. of salt;naphthalene (CIGHS) which lmelts at 184 F. and has a heat of fusion of64 Btu/1b.; cyanamide (HZNCN) which melts at 109.4o F. and exhibits aheat of fusion of 89 Btu/lb. etc. Another substance is a material knowncommercially as Transit-Heet comprising trisodium phosphate and waterwhich melts between 150 and 155 F.

Examples of heat exchanging evaporator uid include Freon 11 (CCISF)which boils at 75.3 F. 1 and has aheat of vaporization of about 78Btu/lb.; Freon 113 (CCl2F-CC1F3) which boils `at 117.6 F. at a heat ofvaporization of about 63 Btu/lb.; ethyl ether [(C-H5)2O] which boils at94.5 F. 1 and exhibits a heat of vapor-ization of about 150 Btu/lb.;acetone [(CH3)2CO] which boils at 133.5 F. 1 and has a heat ofvaporization of about 225 Btu/lb.; etc.

Assn-ming that the selected portion of the heat assembly to be heated isthe oi-l pan containing between 5 to 6 quarts of oil (weighing about 11lbs.) and that its temperature is to be raised from about 0 F. to 60 F.,the amount of B.t.u.s necessary at `an approximate specific hea-t ofabout 0.5 B.t.u. per lb. of oil would be in the neighborhood of about330 B.t.u. Assuming a heat-storage unit containing about 8 lbs. ofsodium dibasic phosphate heated to about 200 `l". and an evaporatorcontaining sufficient Freon 11 to maintain a continuous ow of luid inthe heat-transfer circuit and ignoring the super heat in the salt whichis considerable, the heat of fusion (SXlZt) or 960 B tu.) should yieldsufficient heat at 35% heat transfer etiiciency (960x 0.35 or 336`B.t.u.) to raise the temperature of the oil reservoir sufiiciently toalleviate performance difficulties.

As stated hereinbefore, by having `an automatic valve 4.?. shown in FlG.1, the operation of which depends upon the temperature-sensing device43, the amount of heat transferred can be controlled. For example, whenvalve 42 is olf, the container 31 is emptied of its uid in due course,after which heat ltransfer to the engine assembly virtually ceases. Theheat conducting lines 33, 35 of FIG. 1 and 50, 54 of FIG. 2 shouldpreferably be of non-conductive material so that heat loss to theenvironment is maintained at a minimum. Preferably, the lines should beinsulated at least to the point of maintaining a substantial drop inheat loss from the system.

The heat-storage means may be adapted to get its heat charge from anexhaust-pipe heat exchanger, which is shown in FlG. 4a symbolized by theelement 6b corresponding in function to that of FlG. 4. Thus, while theengine assembly is in operation, heat from the exhaust could be storedin the heat-storage means for eventual use in alleviating startingdiliiculties when the engine is cold. Various combinations of electricaland exhaust heating may also be employed.

in order to promote faster heat exchange between the heat-transfer fluidand the engine part to be warmed, heat-exchange tins may be utilizedsurrounding heattransfer tubing immersed, for example, in the oil pan.As an alternative, the oil pan itself (eg. 25 or" FIG. l) may be formedfrom a two-ply, roll-bonded sheet aluminum in which a maze of tubularpathways are provided between two aluminum sheets bonded together atpredetermined areas, utilizing a resist material to prevent bonding atother predetermined areas defining a continuous pathway.

Although the present invention has been described in conjunction withpreferred embodiments, it is to be understood that modifications andvariations may be resorted to without departing from the spirit andscope of the invention, as those skilled in the art will readilyunderstand. Such modifications and variations are considered to bewithin the purview and scope of the invention and appended claims.

What is claimed is:

1. in a heat-engine assembly powered by the combustion of a hydrocarbonfluid and having selected portions the performance of at least one ofwhich during starting of the engine is adversely affected by asub-freezing ambient temperature, the combination of a selectivewarmllfoiling temperatures are handbook figures, for atmosphericpressure.

up device comprising means for receiving a direct application of heat,heat-storage means associated with said means for receiving directapplication of heat, said heatstorage means having contained therein aheat-storage material characterized by a relatively high heat of fusion,a first heat-exchanger means in heat-exchanging relationship with saidheat-storage means, a second means in heat-exchanging relationship withsaid at least one selected portion of said heat engine assembly which isadversely affected by said sub-freezing temperature, and heat-transfermeans connectably associated with said rst and second heat-exchangermeans.

2. In a heat-engine assembly powered by the combustion of a hydrocarbonhuid and having selected portions the performance of at least one ofwhich during starting oi the engine is adversely aiiected by asub-freezing ambient temperature, the combination of a selective warm-updevice comprising means for receiving a direct application of heat, afiuid-conlining heat-exchanger means in heat-exchanging relationshipwith said heat-receiving means, a heat exchanger condensing means inheat-exchanging relationship with said at least one selected portion ofsaid heat-engine assembly which is adversely affected by saidsub-freezing temperature, fluid-transfer means connectably associatedwith said uid-coniining heat-exchanger means and said heat-exchangingcondensing means, and control means associated with said heattransfermeans for controlling heat transfer from said heat-receiving means tosaid at least one selected portion of said heat-engine assembly.

3. ln a heat-engine assembly powered by the combustion of a hydrocarbonfluid and having selected portions the performance of at least one ofwhich during starting of the engine is adversely affected by asub-freezing ambient temperature, the combination of a selective warm-updevice comprising heat-storage means adapted to receive a directapplication of heat, an evaporator in heat-conductive relationship withsaid heat-storage means, a condenser in heat-exchanging relationshipwith said at least one selected portion of said heat-engine assemblywhich is adversely affected by said sub-freezing temperature,Huid-conducting heat-transfer means connectably associated with saidevaporator and said condenser, and control means associated with saidfluid-conducting means for eifecting heat transfer from said evaporatorto said selected portion of said heat-engine assembly.

4. The device of claim 3 wherein the control means comprises a temerature-sensing means associated with said at least one selected portionof said heat-engine assembly coupled to a valve associated with thehuid-conducting means and adapted to actuate said valve in accordancewith the temperature sensed.

5. ln a heat-engine assembly powered by the combustion of a hydrocarbonfluid and having selected portions the performance of at least one ofwhich during starting of the engine is adversely affected by asub-freezing ambient temperature, the combination of a selective warm-updevice comprising a heat-storage means containing a fusible chemicalcapable of high heat content, said means being adapted to receive adirect application of heat, an evaporator in heat-conductiverelationship with said heatstorage means, a condenser in heat-exchangingrelationship with said at least one selected portion of said heatengineassembly which is adversely atected by said subreezing temperature, ahuid-transfer tube coupling said evaporator to said condenser, afluid-return tube from said condenser and connected via an oit-on valveto said evaporator, and temperature-sensing means associated with saidat least one selected portion of said engine assembly and coupled tosaid oit-on valve for actuating said valve in accordance with thetemperature at said selected portion.

6. In combination, a heat-engine assembly having a part adverselyaffected by sub-freezing ambient temperatures, a sealed thermodynamicsystem comprising an evaporator and a condenser, said condenserincluding a part in direct heat-exchanging relation with said enginepart, said system further including a conduit connecting the upper partof said evaporator with said condenser and including a return-flowcondensate conduit connected to the lower part of said condenser and forreturning condensed heat-exchange fluid to said evaporator, heat-storagemeans in heat-conductive relationship with said evaporator, saidheat-storage means including heat-exchanger means adapted to directlyreceive heat for transmission in the vapor phase to said engine part byWay of said evaporator and said first conduit and said condenser.

References Cited in the le of this patent UNITED STATES PATENTS BergdonNov. 2l,

Oaks May 16,

Backus Nov. 1l,

Nallinger Sept. 28,

FOREIGN PATENTS Sweden Sept. 19,

1. IN A HEAT-ENGINE ASSEMBLY POWERED BY THE COMBUSTION OF A HYDROCARBONFLUID AND HAVING SELECTED PORTIONS THE PERFORMANCE OF AT LEAST ONE OFWHICH DURING STARTING OF THE ENGINE IS ADVERSELY AFFECTED BY ASUB-FREEZING AMBIENT TEMPERATURE, THE COMBINATION OF A SELECTIVE WARMUPDEVICE COMPRISING MEANS FOR RECEIVING A DIRECT APPLICATION OF HEAT,HEAT-STORAGE MEANS ASSOCIATED WITH SAID MEANS FOR RECEIVING DIRECTAPPLICATION OF HEAT, SAID HEATSTORAGE MEANS HAVING CONTAINED THEREIN AHEAT-STORAGE MATERIAL CHARACTERIZED BY A RELATIVELY HIGH HEAT OF FUSION,A FIRST HEAT-EXCHANGER MEANS IN HEAT-EXCHANGING RELATIONSHIP WITH SAIDHEAT-STORAGE MEANS, A SECOND MEANS IN HEAT-EXCHANGING RELATIONSHIP WITHSAID AT LEAST ONE SELECTED PORTION OF SAID HEAT ENGINE ASSEMBLY WHICH ISADVERSELY AFFECTED BY SAID SUB-FREEZING TEMPERATURE, AND HEAT-TRANSFERMEANS CONNECTABLY ASSOCIATED WITH SAID FIRST AND SECOND HEAT-EXCHANGERMEANS.